Internal combustion engines are known to produce blow-by gases during operation. Blow-by gas is produced when some portion of the fuel/air mixture that burns in the combustion chamber is forced past the piston rings during the compression stroke or in the following power stroke. Blow-by gas flow increases with engine wear, usually due to piston rings losing some of their sealing ability with age/wear. This blow-by gas may become saturated with engine oil as it proceeds into the crankcase area of the engine. Engine blow-by is always accompanied by increased pressure in the engine crankcase, which, if not addressed, can cause engine and crankcase seals to leak.
One old and environmentally undesirable solution is to vent engine blow-by gases to the atmosphere such as through an oil fill and vent cap.
Another well known solution is to vent the blow-by gases back into the engine air intake system through a one-way crankcase pressure relief valve, also known as a PCV valve. Blow-by gases may be saturated with oil mist and vapors, so to avoid fouling deposits it is undesirable to directly reintroduce oil laden blow-by gases into the engine air intake system.
A variety of devices have been applied in attempts to remove oil from blow-by gases so as to keep oil out of the engine air intake duct. One such device is a filter having an oil coalescing filter media. This approach introduces other problems as the filter media eventually saturates with oil and becomes an obstruction to blow-by gas flow.
Another known device to remove oil from blow-by gas is a cyclonic oil mist separator. Cyclonic separators have advantages in that they have no moving parts and are resistant to oil fouling or oil plugging.
In conventional air/oil separating PCV systems, it is preferred and normal practice to tool the housing and components laterally (in-line with air flow through the intake duct). Although this approach is often preferred, it is not always feasible when system geometry is not conducive to the approach.
As can be seen, there is a need for an improved air/oil separating PCV apparatus that allows tooling of molded housing components in a vertical direction, particularly when its required shape and configuration is not conducive to lateral tooling.